Mining



(No Model.) I

. J. ORITES.

MINING.

No. 489,812. Patented Nov. 4, 1890.

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.IOI-IN \V. CRITES, OF SAN FRANCISCO, CALIFORNIA.

MINING.

SPECIFICATION forming part of Letters Patent No. 439,812, dated November 4, 1890. Application filed March 6, 1890. Serial No. 342,913. (No model.)

To all whom it may concern.-

Be it known that I, JOHN W. CRITES, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented new and useful Improvements in Mining; and I do hereby declare the following to be a full, clear, and exact description thereof, such as will enable others skilled in the art to which my invention appertains to make and use the same.

My invention relates to the mining of riverchannels; and its object is to provide an easy and comparatively inexpensive means of getting at the mineral deposits lying therein.

I-Ieretofore it has been found necessary in the mining of river-beds to construct a dam in order to divert the water from its regular course, and therebyuncover the precious metals. This naturally entails a large outlay without a certitude of adequate returns, and as a matter of fact the enterprise is so full of risks and it has so often proved unremunerative that this class of mining has been practically abandoned, notwithstanding that rich ore deposits are known to exist at the bottom of rivers in metalliferous districts. I have discovered that a dam is not an essential feature in river-mining, and that, indeed, much better results can be obtained by draining the water off the river-bottom in selected spots instead of damming the whole channel, and this I accomplish through the medium of a peculiarlyconstructed apparatus, which I will now proceed to describe.

Referring to the accompanying drawings, which form part of this specification, Figure 1 is a plan of the improved appliance which I use for carrying out my new method of mining, and Fig. 2 is a sectional elevation of the same.

The same letters of reference indicate the same parts in both views.

Let Arepresent a raft, ponton, or boat 11aving a central opening B. By preference the fore part a is reserved for living-quarters, while the stern bis utilized for engine and tool rooms. Both ends are connected by passages c c on each side of the'opening B, said passages being formed by the inner and outer walls of the raft, as clearly shown in Fig. 2 of the drawings.

0 O are large air or water pipes secured all around the bottom of the raft, in order to increase or decrease its buoyancy, as circumstances may require, the air or water being let in or expelled from them.

In the opening B, I place an open tank or caisson D, made of iron or othersuitable ma terial. This caisson is vertically movable and adjustable within the opening. It may be lowered to the river-bottom by various means; but I prefer for this purpose the use of-racks and pinions (not shown) secured,respectively, to the outer sides of the caisson and the inner sides of the raft, the whole being worked from the engine E. Thus the caisson is not only rendered portable and easily removed from one point to another with the boat, but it is readily and quickly adapted to the varying depths of the river-bed. Leaves or extension-pieces (not shown) fitted to be fastened to the upper edges of the caisson are employed in very deep places; but they are unnecessary in ordinary cases, as the raft may be sunk low enough through the medium of the pipes O C to insure the working of a caisson of common height.

The caisson being once driven into the riverbottom, I empty it of its water by means of a series of centrifugal pumps F, placed at suitable points and operated by the engine. These pumps are constantly kept at work, even after the earth is uncovered, as it is needless to always sink the caisson down to the bed-rock, and there is more or less seepage-water oozing out of the ground.

The mineral deposits are secured in the ordinary manner and then conveyed by an elevator G to a sluice-box H on one side of the raft, where they are washed with the same water which is pumped out of the caisson. This operation is of course kept up until no more pay-dirt is found, when the caisson is lifted and the boat moved to where there is any reasonable prospect of obtaining more ore.

It is apparent that by using the above method one is enabled to mine a river-channel just as eifectnally as if the whole riverbed were laid bare without going to great expense. Moreover, an apparatus of the kind described will answer the purpose of a hundred dams, inasmuch as it can be located at any desired point throughout the whole length of a riy'er. Thus I afford a very cheap and convenient ineans of developing the natural resources of the country and make it possible to carry on river-mining with little risk and a fair chance of success.

Having described my invention, What I claim as new, and desire to secure protection 1n by Letters Patent of the United States, is-

1. In an apparatus for mining river-channels, the combination, with a raft, ponton, or boat provided with a central opening, of a caisson adapted to be sunk through said opening and air or water pipes arranged around said raft, ponton, or boat and adapted to increase or decrease the buoyancy thereof, substantially as set forth.

2. In an apparatus for mining river-channels, the combination, witha raft, ponton, or

- boat provided with a central opening and having its deck portion upon each side of said openin g formed into passages communicating at the fore and aft of the boat, of Water or air pipes arranged around said raftand beneath the passages, substantiallyas set forth. 3. In an apparatus for mining river-channels, the combination, with a raft, ponton, or boat provided with a central opening andhaving the deck portion upon each side of said opening formed into passages communicating at the fore and aft of the boat, of a caisson disposed Within the opening, a bucket-elevator within said caisson, a standard projecting from one of the side passages of the boat, a sluice-box supported by said standard, and pumps adapted to drain the water off said caisson and from it into said sluice-box, substantially as set forth.

In testimony whereof I have hereunto set my hand and affixed my seal. 

